Intra-annular mounting frame for aortic valve repair

ABSTRACT

An intra-annular mounting frame for an aortic valve having native aortic cusps is provided which includes a frame body with native leaflet reorienting curvatures and interconnecting points; the curvatures shaped to be received inside the valve below the native aortic cusps and to reorient the native aortic cusps within the aortic valve, where each of the curvatures extends concavely upward from a reference latitudinal plane tangential to each curvature&#39;s base.

RELATED APPLICATIONS

This application is a continuation in part of U.S. patent applicationSer. No. 13/868,011, filed on Apr. 22, 2013, which is a continuation ofU.S. patent application Ser. No. 13/453,914, filed on Apr. 23, 2012,which is a continuation of U.S. patent application Ser. No. 11/799,942,filed on May 3, 2007 (now issued as U.S. Pat. No. 8,163,011), whichclaims the benefit of priority to U.S. provisional Patent ApplicationNo. 60/849,919, filed on Oct. 6, 2006, each of which is herebyincorporated by reference its entirety. This application is also acontinuation in part of U.S. patent application Ser. No. 13/249,621,filed on Sep. 30, 2011, which claims the benefit of priority to U.S.provisional Patent Application No. 61/388,573, filed on Sep. 30, 2010,each of which is which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The present disclosure relates to a mounting frame useful forapplications including aortic valve repair, and more particularly, inbicuspid aortic valve repair. More particularly, the present disclosurerelates to an intra-annular mounting frame which is inserted directlyinto the aortic valve annulus. The disclosure also includes methods forthe insertion and implantation of an intra-annular mounting frame, aswell as complementary devices, such as ascending aortic Dacron® graftsand pericardial single cusp prostheses.

BACKGROUND

The mammalian heart is essentially a pump that functions as achemo-mechanical energy transducer. The chemical energy of metabolicsubstrates and oxygen is converted into the mechanical energy of bloodpressure and flow by myocardial sarcomeres during cardiac contraction.The pump is periodic at a frequency of 1-2 Hz, with thecontraction/ejection phase called systole and the relaxation/fillingphase termed diastole.

The human heart is the center of the cardiovascular system, the systemhaving two parallel circulations consisting of the pulmonary circulationand the systemic circulation. The pulmonary circulation receives bloodfrom the venae cavae into the right atrium and right ventricle, and thenpumps the cardiac output into the pulmonary arteries and through thelungs. The systemic circulation receives blood from the pulmonary veins,pumps the cardiac output through the left atrium and left ventricle tothe aorta, systemic arteries, capillaries, and veins, and finallytransmits blood back to the venae cavae. The mitral valve is positionedbetween the upper chamber, the left atrium, and the pumping chamber, theleft ventricle. The left atrium acts in a capacitor function receivingblood from the lungs via the pulmonary veins throughout the cardiaccycle. The left ventricle fills during diastole by receiving blood fromthe left atrium as the mitral valve opens, and then during systole, themitral valve closes and permits forward ejection of the blood from theleft ventricle into the ascending aorta. The aortic valve is locatedbetween the left ventricle and aorta, and functions under normalconditions to allow unimpeded blood flow out of the ventricle and intothe aorta during systole. During diastole, the aortic valve closes andprevents regurgitation backward into the left ventricle.

Surgical reconstruction of a patient's native valve is becoming standardfor mitral valve disease. Whether considering mitral valve prolapse,pure annular dilatation, ischemic mitral regurgitation, or mitralendocarditis, repair is now routine, highly successful, and associatedwith low late failure rates. Even in rheumatic mitral disease, manysurgeons are embarking on programs of aggressive repair, adding to ringannuloplasty the techniques of posterior leaflet augmentation withgluteraldehyde-fixed autologous pericardium, resection of the stenoticsubmitral apparatus with insertion of artificial Gortex® chords, leafletdecalcification, etc. The current goal is to achieve close to a 100%repair rate of mitral valve disorders and to markedly diminishprosthetic valve replacement. The advantages of repair versusreplacement in this setting are well documented. The operative mortalityrate (normalized for other factors) is lower, anticoagulation is notrequired in sinus rhythm, valve-related complications are less than withprosthetic valves, durability is excellent because the patent's owntissues do not degenerate, and late endocarditis is reduced because lessforeign material is present. As such, these concepts for mitral valvedisease are rapidly becoming standard-of-care in the field of cardiacsurgery.

The aortic valve of a human heart can also become diseased, with aorticvalve insufficiency occurring from a number of causes. A common cause isannular dilatation, with the sinuses of the Valsalva migrating outwardand the inter-commissural distances expanding. Geometrically, thisderangement not only increases the annular circumference, but alsoreduces the surface area of cusp coaptation. The coaptation angle of thecusps is changed essentially from being parallel and meeting at an acuteangle to pointing at each other, wherein the cusps comprise a moreobtuse arrangement. Eventually, a central gap of coaptation occurs andincreasing aortic insufficiency begets more annular dilatation whichbegets more aortic insufficiency and the leak progressively increases.

While aortic valves are typically tricuspid, having three leaflets (orcusps) approximately 2% of the population has a bicuspid aortic valve. Abicuspid aortic valve is understood to be a congenital defect, which maybe inherited, wherein two of the three leaflets fuse together at anearly stage of embryonic development, resulting in a valve having onlytwo leaflets. A bicuspid valve may function normally for years, butbecome diseased later on in life.

Repair of a diseased aortic valve has not been met with the same successas experienced in reconstructing a diseased mitral valve. For about 10to 15 years, the “commissural annuloplasty” technique has been used, butit can only be applied to mild-to-moderate secondary aorticinsufficiency, usually in patients undergoing primary coronary bypass ormitral valve procedures. Commissural annuloplasty not only decreasesannular circumference, but also tends to move the sinuses centrally,thus normalizing geometry and coaptation angles of the cusps. There is alimit, however, to the geometric abnormality that commissuralannuloplasty can normalize, and because the entire annulus is not fixedby this procedure, the potential for further dilatation and recurrentaortic insufficiency exists. As such, other devices and methods havebeen proposed including, for example, Carpentier et al. (U.S. Pat. No.4,451,936) which teaches a supra-annular aortic valve. According toCarpentier et al., the invention is applicable to mechanical heartvalves and leaflet-type heart valves, and does not project into theaortic valve.

In Duran et al., U.S. Pat. No. 5,258,021, an annuloplasty ring isdescribed for insertion inside the aorta in the supra-annular regionabove the aortic valve annulus. The disclosed device appears circularfrom above and has three substantially sinusoidal shaped struts.

U.S. Pat. No. 6,231,602, Carpentier et al. describes an annuloplastyring sutured to the tissue above the aortic valve annulus and also aninfra-annular ring which can be sutured to the dense tissue immediatelybelow the commissural-arterial wall intersection. Moreover, theinfra-annular ring does not alter or even influence leaflet geometry inan organized manner, but instead constricts the infra-annular aorta tomove the inferior aspects of the leaflets centrally rather than restoreproper leaflet coaptation. Furthermore, as the ring of the '602 patentis apparently based on previous studies of the mitral valve, the '602neglects the complexities of the 3-dimensional geometry of the aorticvalve and ineffectively constricts either the supra-valvular orinfra-valvular area. Also, the '602 patent describes the ring as onlyfollowing the rough shape of the aortic tissue either above or below thevalve annulus and neither provides an explanation of the proper sizingof the ring nor describes how the ring will be implanted within thepatient.

In Marquez, U.S. Published Patent Application No. 2005/0228494, a heartvalve frame is described which can separate into a plurality ofindividual cusps after implantation. Additionally, the invention of the'494 patent application is preferably used with synthetic leaflets.

Unfortunately, supra- or infra-annular rings and artificial valves ofthe prior art processes are generally not effective for the long termimprovement of the aortic valve, and additionally, may require quitecomplicated surgical procedures. The rings currently described forinsertion into the aorta are designed to be inserted above or below thevalve. Suturing a ring below the aortic valve (infra-annular) to simplydownsize or constrict the circumference will negatively distort thevalve cusps and can lead to worsening valve leak. Furthermore, theconstriction concept ignores the fact that the three semi-lunar aorticvalve cusps are three-dimensional structures that are required to meetin space in a specific orientation to provide valve competence.Similarly, the supra-annular rings of the prior art are laden with thesame problems, and have even less geometric basis, since thesupra-annular rings only quite roughly follow the shape of the aortictissue above the annulus and are based on no tangible geometric model.

What is desired, therefore, is a mounting frame which is inserteddirectly into a an aortic valve annulus to repair the aortic valve.Indeed, a combination of characteristics, including thethree-dimensional aspects of the aortic valve, has been found to beimportant for returning aortic valvular geometry to normal. Also desiredis a process for inserting and mounting such frames. It is also desiredto provide an intra-annular mounting frame for insertion into abiscuspid aortic valve.

SUMMARY OF THE INVENTION

The present disclosure accordingly provides an intra-annular mountingframe which is uniquely adapted to the three-dimensional characteristicsof the aortic valve, and in particular embodiments, a bicuspid aorticvalve. The intra-annular mounting frame exhibits a design with carefulconsideration toward the anatomical features of the aortic valve anatomyso that valve competence is restored.

More particularly, the present intra-annular mounting frame includescurvatures with curves in at least a first and a second plane to conformto the geometry of the cusps and also interconnecting points to conformto the normal commissural anatomy of the aortic valve. In oneembodiment, three curvatures comprise the frame with each curvatureadjoined to the other at a pointed peak conformed to the geometriccharacteristics of each commissure. In a preferred embodiment, a shortpost can extend up from each point to the commissure. These posts have aheight that is equal to the equivalent radius of the aortic valve, andwould suspend the commissure and each cusp in the proper threedimensional parallel relationships to allow complete coaptation. In someembodiments, the frame has two points, two post and two curvatures.

In some embodiments, the frame comprises two curvatures and two posts.The first curvature may be about the same length of the second curvatureor the length may be about 30% larger than the length of the secondcurvature.

In alternative embodiments of a frame having two posts, the positionsmay vary in on the circumference of the frame. For example, the postsmay be positioned anywhere from about 90° to about 180° apart on theframe.

In some embodiments, the intra-annular mounting frame has a roughlyelliptical shape having a major axis and a minor axis. The ratio of themajor axis can range from about 1 to about 1.8. Thus, the presentdisclosure provides an intra-annular mounting frame having either acircular wherein the axes are approximately equal or an elliptical shapehaving a major axis and a minor axis, wherein the major axis is greaterin length than the minor axis. In certain embodiments the intra-annularmounting frame comprises three curvatures, three points, and threeposts. A circumferential distance (distance around the perimeter of theellipse) is defined between each of the posts in the intra-annularmounting frame. In some embodiments, generally depending upon thespecific geometry of the aortic valve of the patient, thecircumferential distance between each of the posts are equal(symmetrical), in other embodiments the circumferential distance betweeneach of the posts are different (asymmetrical), while in yet otherembodiments two of the circumferential distances between the posts areequivalent while the third circumferential distance is different fromthe other two (also asymmetrical).

In further embodiments the intra-annular mounting frame comprises twocurvatures, two points, and two posts. Such embodiments are used inbicuspid aortic valve repair. In certain embodiments, generallydepending upon the specific geometry of the bicuspid aortic valve of thepatient, the circumferential distance (distance around the perimeter ofthe ellipse) between each of the posts are equal (symmetrical), while inother embodiments the circumferential distance between each of the postsare different (asymmetrical). In additional embodiments the posts arelocated along the curvatures defined by the major axis of the ellipse,the curvatures defined by the minor axis of the ellipse, or one post islocated along the curvatures defined by the major axis of the ellipsewhile the other post is located along the curvatures defined by theminor axis of the ellipse.

In particular embodiments, again generally depending upon the specificgeometry of the aortic valve of the patient, the ratio of the major axisof the ellipse to the minor axis of the ellipse is greater than 1, incertain aspects between about 1.1 and 1.8, including ratios of about1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7,and about 1.8. The ellipse defined by the intra-annular mounting framecan also be expressed as the ratio of the minor axis to the major axis.As such, the presently described intra-annular mounting frame can have aratio of the minor axis to the major axis of less than 1, in certainaspects about 0.9, about 0.85, about 0.80, about 0.75, about 0.70, about0.65, about 0.60, or about 0.55 or so. In various embodiments the lengthof the major axis of the ellipse is between about 10 millimeters andabout 35 millimeters, between about 15 millimeters and about 30millimeters, between about 20 millimeters and about 25 millimeters,between about 10 millimeters and about 30 millimeters, between about 10millimeters and about 25 millimeters, between about 10 millimeters andabout 20 millimeters, between about 10 millimeters and about 15millimeters, between about 15 millimeters and about 35 millimeters,between about 20 millimeters and about 35 millimeters, between about 25millimeters and about 35 millimeters, or between about 30 millimetersand about 35 millimeters, including lengths of about 10 millimeters,about 11 millimeters, about 12 millimeters, about 13 millimeters, about14 millimeters, about 15 millimeters, about 16 millimeters, about 17millimeters, about 18 millimeters, about 19 millimeters, about 20millimeters, about 21 millimeters, about 22 millimeters, about 23millimeters, about 24 millimeters, about 25 millimeters, about 26millimeters, about 27 millimeters, about 28 millimeters, about 29millimeters, about 30 millimeters, about 31 millimeters, about 32millimeters, about 33 millimeters, about 34 millimeters, and about 35millimeters. The length of the minor axis of the ellipse can also vary,for example between about 8 millimeters and about 25 millimeters,between about 10 millimeters and about 21 millimeters, between about 14millimeters and about 18 millimeters, between about 8 millimeters andabout 20 millimeters, between about 8 millimeters and about 15millimeters, between about 10 millimeters and about 25 millimeters,between about 15 millimeters and about 25 millimeters, or between about20 millimeters and about 25 millimeters, including lengths of about 8millimeters, about 9 millimeters, about 10 millimeters, about 11millimeters, about 12 millimeters, about 13 millimeters, about 14millimeters, about 15 millimeters, about 16 millimeters, about 17millimeters, about 18 millimeters, about 19 millimeters, about 20millimeters, about 21 millimeters, about 22 millimeters, about 23millimeters, about 24 millimeters, and about 25 millimeters.

The frame may be constructed of a variety of materials including metals,polymers, thermoplastics, plastics, and other materials which will allowfor slight deformation but will not sheer under normal stresses.Conceivably, the frame could be a perforated strip of metal or plasticso as to allow the sutures better purchase upon mounting the frame.

Additionally, the frame may optionally be covered with a Dacron®(polyethylene terephthalate) cloth, thus utilizing the same materials asin current mitral valve annuloplasty ring designs, or alternatively, theframe may be covered with gluteraldehyde-fixed bovine pericardium orGortex® material (expanded polytetrafluoroethylene).

The intra-annular mounting frames may embody a variety of sizes to matchthe intra-cusp volume and geometry of the aortic valve of differentpatients. In practical use, the intra-annular mounting frame would rangein sizes from about 16 millimeters to about 30 millimeters in mostpatients.

Generally, the intra-annular mounting frame can be implanted into theaortic valve annulus in a variety of ways. A first method includes smallfabric strips, pledgets, or pads with a combination of mattress suturesto firmly suture the intra-annular mounting frame to the aortic valveannulus, while reducing tearing of the aortic tissue. Alternatively,complementary single cusp arcs with curvatures similar to the multipleshield curves may be employed above the cusps into which sutures may beinserted so that the patient's cusps would be “sandwiched” between thesemi-rigid intra-annular mounting frame and the supporting arcs above.

An object of the present disclosure, therefore, is an intra-annularmounting frame having characteristics which reconstruct the normalthree-dimensional characteristics of the aortic valve.

Still another object of the present disclosure is an intra-annularmounting frame having curvatures with curves in at least a first and asecond plane so that the frame is substantially conformed to the annularcusp geometry of the aortic valve.

Yet another object of the present disclosure is an intra-annularmounting frame having points interconnecting each curvature whichconform to the geometry of the area around the commissures of the valve.

Another object of the present disclosure is an intra-annular mountingframe having posts corresponding to each interconnecting point whichassists in suspending the commissures and cusps in a properthree-dimensional relationship.

Another object of the present disclosure is a method of implanting theintra-annular mounting frame to the aortic valve annulus with suturesextending from below the cusps to an area above the cusps.

Yet another object of the present disclosure is a method of implantingthe intra-annular mounting frame which includes at least one support arcemployed above the valve annulus similar in shape to the curvatures ofthe mounting frame.

Still another object of the present disclosure is a method of modelingthe intra-annular mounting frame by measuring at least one dimension ofa patient's aortic valve.

Another object of the present disclosure is a method of sizing theintra-annular mounting frame by an integration of modeling parametersinto a diagnostic device.

These aspects and others that will become apparent to the artisan uponreview of the following description can be accomplished through the useof an intra-annular mounting frame designed with considerableconsideration to the three-dimensional geometry of the aortic valve. Theinventive intra-annular mounting frame advantageously reconstructsproper cusp and commissure relations so that normal coaptation isachieved.

It is to be understood that both the forgoing general description andthe following detailed description provide embodiments of the presentdisclosure and are intended to provide an overview or framework ofunderstanding the nature and character of the invention as is claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of an embodiment of an intra-annular mountingframe.

FIG. 2 is an illustration of another embodiment of the intra-annularmounting frame.

FIG. 3 is an illustration of a supra-valvular view of normal aorticvalve.

FIG. 4 is an illustration of a supra-valvular view of a diseased aorticvalve.

FIG. 5 is an illustration of a dissected aortic valve openedlongitudinally through a commissure.

FIG. 6 illustrates a first embodiment of the intra-annular mountingframe in a longitudinally opened position, overlaid on a longitudinallyopened normal aortic valve and laid flat.

FIG. 7 illustrates a second embodiment of the intra-annular mountingframe in a longitudinally opened position, overlaid on a longitudinallyopened normal aortic valve and laid flat.

FIG. 8 illustrates a first embodiment of mounting the intra-annularmounting frame opened to display a suture configuration with an aorticvalve.

FIG. 9 illustrates a second embodiment of mounting the intra-annularmounting frame.

FIG. 10 illustrates a top view of the second embodiment of theintra-annular mounting frame.

FIG. 11. Perspective view of one embodiment of a bicuspid ellipticalintra-annular mounting frame of the present disclosure.

FIG. 12. Front elevational view of the embodiment of the bicuspidelliptical intra-annular mounting frame shown in FIG. 11.

FIG. 13. Top view of the embodiment of the bicuspid ellipticalintra-annular mounting frame shown in FIG. 11.

FIG. 14. Side view from “D” (see FIG. 13) of the embodiment of thebicuspid elliptical intra-annular mounting frame shown in FIG. 11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Although the products and methods according to the present invention aredisclosed herein as being useful for and in the context of aortic valverepair, both the products and methodology may also be used in otherfields including, but not limited to, surgical procedures for the repairof other valves within the human body.

Referring generally now to FIG. 1, an intra-annular mounting frameuseful for aortic valve repair is shown and generally designated asnumeral 10. Intra-annular mounting frame 10 is inserted into the aorticvalve annulus and provides for the reconstruction of the native aorticvalve.

Intra-annular mounting frame 10 includes a plurality of curvatures 12and also interconnecting points 14. Generally, curvature 12 conforms tothe annular cusp geometry with interconnecting points 14 conforming tothe geometry of the commissures. Curvatures 12 curve in about a firstplane and a second plane of mounting frame 10 to correspond to thethree-dimensional geometry of the cusps of an aortic valve. Forreference, the latitudinal plane is defined as the horizontal plane onwhich intra-annular mounting frame 10 would rest with each curvature 12contacting the latitudinal plane similarly. The longitudinal plane isdefined as the plane which intersects the latitudinal plane at aperpendicular angle and runs vertically through intra-annular mountingframe 10. Curvatures 12 may curve in both the latitudinal andlongitudinal planes and in optional embodiments the curvatures may curvein multiple other planes. Preferably, curvature 12 curves in at leasttwo planes to correspond to the three-dimensional geometry of the aorticvalve with curvature 12 in contact with the wall while providing supportand alignment to the aortic valve cusps. Furthermore, interconnectingpoints 14 serve the dual function of interconnecting curvatures 12 whilealso providing support to the commissures of the aortic valve.Specifically, interconnecting points 14 are designed to closely fit thethree-dimensional geometry between adjacent cusps and locate near thecommissures thus providing support and assistance in the restoration ofthe proper coaptation of the cusps. Each point of interconnecting points14 continuously narrows into a tip so that each point fits within thenarrowing space between adjacent cusps which culminates in a commissure.As such, interconnecting points 14 provide support within thisinter-cusp space to immediately below the commissures.

FIG. 2 illustrates a preferred embodiment of intra-annular mountingframe 10 with posts 16 extending up from interconnecting points 14.Posts 16 function as to suspend the commissures of the aortic valve aswell as the cusps in proper three-dimensional parallel relationships toallow complete coaptation when implanted in an aortic valve. Differentfrom the embodiment in FIG. 1, interconnecting points 14 of theembodiment displayed in FIG. 5. do not extend significantly into thenarrowing space between adjacent cusps, but rather posts 16 extend assuch. Otherwise stated, the tip of interconnection points 14 of FIG. 4.is at about the same height as the tip of post 16 of the embodiment inFIG. 2. In order to fully understand the design characteristics of themultiple embodiments of intra-annular mounting frame 10, it is necessaryto understand and consider the three-dimensional relationships withinthe anatomy of the aortic valve.

FIG. 3 illustrates a cross-sectional view of normal aortic valve 18 withaortic wall 20, cusps 22 and commissures 26. Aortic valve 18, while notperfectly circular in actuality, is most often within the art,prescribed measurements typically attributable to a cylindrical objectin order to provide ease in the measurements and calculations associatedwith aortic valve 18. As such, each of cusps 22 attach to aboutone-third of the circumference of aortic wall 20 while meeting incoaptation in the center of aortic valve 18. Commissures 26 are definedas the juncture points where adjacent cusps 22 attach to aortic wall 20.While FIG. 3 only illustrates the two-dimensional aspects of normalaortic valve 18, a complex three-dimensional orientation is necessaryfor both cusps 22 and commissures 26 to align in the proper coaptationas is illustrated.

FIG. 4 illustrates a cross-sectional view of a diseased aortic valvewith aortic wall 20, cusps 22, and also aortic valve leak 24. Leak 24,as illustrated in FIG. 4, may be a result of dilation of aortic annulus18, and as a result, cusps 22 do not meet in the proper coaptation.Essentially, leak 24 is a central gap of coaptation, resulting in aorticinsufficiency which in turn increases the annular dilation of aorticvalve 18 thus progressively increasing leak 24.

Turning now to FIG. 5, FIG. 5 is an illustration of a dissected aorticvalve 18, opened longitudinally through commissure 26 between two cusps22 and laid flat. Each of the three cusps 22 is illustrated as a“shield-shaped flap” with the two intact commissures 26 visible wherethe adjacent cusps 22 contact to form a point and attach to the aorticwall. Aortic valve 18 is physically characterized by annularcircumference 28 which is the measurement of the linear distance fromone aortic margin 30 to the other aortic margin 30 at the approximatebase of cusps 22. From the annular circumference, the annular diameterand annular radius can be calculated to further define the physicalgeometry of the aortic valve. Furthermore measurements include cuspheight 32 which is defined as the distance from the approximate base ofcusp 22 to upper midpoint of cusp 22 which is generally found to bewithin 1 millimeter of the annular radius in a normal functioning aorticvalve. Cusp length 34 is approximately the measurement of cusp 22 freeedge from one commissure 26 to the next and is also about equal toannular circumference 28 divided by 3 as three cusps 22 comprise thelength of annular circumference 28.

These measurements and calculations were utilized to form intra-annularmounting frame 10 as illustrated in FIG. 3, which is further illustratedtwo-dimensionally in FIG. 6 in a longitudinally opened position,overlaid on a longitudinally opened normal aortic valve and laid flat.While intra-annular mounting frame 10 of the present invention does notopen or break in practice, the two dimensional, longitudinally open viewof FIG. 6 provides for greater ease in illustrating the dimensionalaspects of intra-annular mounting frame 10 in relation to aortic valve18. Each of three curvatures 12 are positioned approximately adjacent tothe three bases of cusps 22 of aortic valve 18. The base cuspscurvatures 12 have an incident of curvature approximately similar to thecurve at which cusps 22 attach to the aortic wall. While notillustrated, in an intact aortic valve, curvatures 12 would also curvein at least one additional plane thus corresponding to the threedimensions of an intact aortic valve. Additionally, the two intactcommissure points 14, as well as the additional commissure point 14 notshown, fit substantially up to each respective commissure 26 of aorticvalve 18. Intra-annular mounting frame 10 height 36 is the approximatedistance from the base of each curvature 12 to each interconnectingpoint 14 which is similar to cusp height 32 of the aortic valve 18.Furthermore, intra-annular mounting frame 10 length 38 is similar ingeometry and dimensions to the annular circumference 28 of aortic valve18.

In another aspect of the present disclosure, FIG. 7 represents theembodiment illustrated in FIG. 2 in a two-dimensional longitudinallyopen view similar to the embodiment of FIG. 1 illustrated in FIG. 6.With this embodiment, posts 16 may extend up to the commissures 26 orslightly past. Most preferably, posts 16 may be of a height equal to theradius of the aortic valve 18 and may suspend the cusps in proper threedimensional parallel relationships to allow for complete coaptation ofthe aortic valve.

Generally, intra-annular mounting frame 10 as embodied in FIG. 1 andFIG. 2 as well as in additional embodiments is substantially similar ingeometry and dimensions to a normal aortic valve. Most often theintra-annular mounting frame will be sized about 2 millimeters less indiameter than the calculated diameter of the aortic valve (based on theleaflet free edge length) into which the intra-annular mounting framewill be implanted, while the incident of curvature of each of the threecurvatures will be similar to the base of the cusps or can be slightlygreater or lesser, partially depending on whether the intra-annularmounting frame includes posts or not on the commissure points and alsopartially depending on the degree of abnormality of the aortic valve.The intra-annular mounting frame can be produced in a variety of sizesand embodiments for providing the correct coaptation of the cusps of theaortic valve. The intra-annular mounting frame circumferential lengthmay be of a variety of sizes depending of the necessary alteration ofthe geometry of the diseased aortic valve. While the intra-annularmounting frame may be considered generally circular when viewed fromabove as illustrated in FIG. 10, which is a top view of the embodimentof the intra-annular mounting frame displayed in FIG. 2, the frame mayinclude minor deviations from a circular arrangement, includingdeviations such as structural flaring.

Most generally, the diameter of the intra-annular mounting frame is fromabout 16 millimeters to about 30 millimeters with a variety of differentsized frames there between, forming a gradient of possible choices toclosely approximate the needs of the patient. Large sizes of theintra-annular mounting frame would be produced so that the presentdisclosure could be utilized with aortic root aneurysms or patients withMarfan syndrome. Furthermore, the intra-annular mounting frame height asmeasured from the base of a curvature to the commissure point may vary,most often being equivalent to the calculated radius of the repairedvalve. Thus, the embodiment as illustrated in FIG. 1, with theintra-annular mounting frame of FIG. 2. would have a measurement fromthe base of the curvature to the top of a post from about (but notexclusively) 8 millimeters to about 15 millimeters. The posts on thecommissure points may be perpendicular to the longitudinal plane of theintra-annular mounting frame and in additional embodiments may angletoward the interior area of the intra-annular mounting frame or outwardaway from the interior area of the intra-annular mounting frame. Theposts may extend away from the interior area of the frame at an angle offrom about 90 degrees to about 120 degrees when measured from theinternal area of a latitudinal plane of the frame. However, in otherembodiments of the asymmetrical intra-annular mounting frame the postsmay extend from a vertical plane of the elliptical intra-annularmounting frame by between about 0° and about 30°. In anotherembodiments, the posts may extend from a vertical plane by about 1° toabout 30°, about 5° to about 15°°, about 8° to about 12° or about 10°.Different orientations and shapes of both the posts as well as theshapes of the curvatures may be utilized to account for the differentanatomic variations. In most embodiments, the curvatures would be fairlysymmetrical to one another as most valves have 3 cusps of equal sizes,though in additional embodiments the intra-annular mounting frame can beproduced in an asymmetrical design as some patients have asymmetricalsinuses. Variations could include an intra-annular mounting frame withone curvature about 20% larger than the other two curvatures, and also avariation with a single curvature sized 20% smaller than the othercurvatures. Additionally, the intra-annular mounting frame may beproduced with two curvatures and two interconnecting points for valveswhere only two cusps are present. Furthermore, additional embodimentscan include a Gore-Tex® coating of the frame as well as include the useof a variety of different polymers to coat the frame's surface.

Generally, the intra-annular mounting frame's curvatures may curve in atleast two planes as the location of the intra-annular mounting framewithin the aortic valve necessitates correspondence to both the curvesof the aortic wall and cusps of the aortic valve, for proper coaptation.

The intra-annular mounting frame is comprised of metal, plastics,thermoplastics, polymers, resins or other materials which will remainintact in spite of potentially high tension caused from a highly dilatedaortic roots. Preferably the intra-annular mounting frame may beconstructed of a solid metal wire, solid plastic, and most preferably aperforated strip of metal or plastic so as to provide the sutures betterpurchase once implanted into the aortic valve. The perforations may varydepending on the installation method, though preferably with the fairlyuniform geometry of the annular region, a set number and position ofperforations for sutures may be created and marked onto theintra-annular mounting frame.

Referring now to FIG. 11, a perspective view of an embodiment of abicuspid elliptical intra-annular mounting frame useful for aortic valverepair is shown and generally designated as numeral 10″. Bicuspidelliptical intra-annular mounting frame 10″ is inserted into the aorticvalve annulus and provides for the reconstruction of the native aorticvalve having only two sinuses. Bicuspid elliptical intra-annularmounting frame 10″ includes two curvatures 12″, interconnecting points14″, and posts 16″. Curvatures 12″ conform to the annular cusp geometrywith interconnecting points 14″ and posts 16″ conforming to the geometryof the sub-commissural region. Curvatures 12″ curve in a plurality ofplanes of bicuspid elliptical intra-annular mounting frame 10″ tocorrespond to the three-dimensional geometry of the two cusps of abicuspid aortic valve. For reference, the horizontal plane is defined asthe plane on which bicuspid elliptical intra-annular mounting frame 10″would rest with each curvature 12″ contacting the plane. The verticalplane is defined as the plane which intersects the horizontal plane at aperpendicular angle and runs vertically through bicuspid ellipticalintra-annular mounting frame 10″. Curvatures 12″ may curve in both thehorizontal and vertical planes, and/or may curve in one or more otherplanes. Generally curvatures 12″ contact the aortic wall and providesupport and alignment to the aortic valve cusps. Interconnecting points14″ and posts 16″ provide support to the commissures of the aorticvalve. Specifically, interconnecting points 14″ and posts 16″ aredesigned to closely fit the three-dimensional geometry between adjacentcusps and locate near the commissures thus providing support andassistance in the restoration of the proper coaptation of the cusps.Interconnecting points 14″ continuously narrow to posts 16″ and thus fitwithin the narrowing space between adjacent cusps that culminates in acommissure. As such, interconnecting points 14″ and posts 16″ providesupport within this inter-cusp space to immediately below thecommissures.

Referring now to FIG. 12, a front elevational view of bicuspidelliptical intra-annular mounting frame 10″ is shown. Bicuspidelliptical intra-annular mounting frame 10″ includes two curvatures 12″,interconnecting points 14″, and posts 16″.

Referring now to FIG. 13, a top view of bicuspid ellipticalintra-annular mounting frame 10″ is shown. Once again bicuspidelliptical intra-annular mounting frame 10″ includes two curvatures 12″,interconnecting points 14″, and posts 16″. As shown in FIG. 13, the baseof bicuspid elliptical intra-annular mounting frame 10″ generallydefines an ellipse, with a major axis denoted by “D” and a minor axisdenoted by “A”. In the embodiment of the bicuspid ellipticalintra-annular mounting frame 10″ shown in FIG. 13, the ratio of themajor axis to the minor axis of the ellipse is about 1.5:1, although inother embodiments of the bicuspid elliptical intra-annular mountingframe (not shown) the ratio of the major axis to the minor axis of theellipse can vary generally between about 1 to about 1.8, about 1.7:1 orabout 1.8:1 or about 1.1:1 or 1.2:1. In addition, the circumferentialdistances (distances around the perimeter of the ellipse) between posts16″ in the embodiment of the bicuspid elliptical intra-annular mountingframe 10″ shown in FIG. 13 are roughly equivalent (symmetric; about 50%of the circumference), although in other embodiments of the bicuspidelliptical intra-annular mounting frame (not shown) the circumferentialdistances between posts 16″ can differ, for example one circumferentialdistance of about 75% of the circumference and the other circumferentialdistance of about 25% of the circumference, one circumferential distanceof about 70% of the circumference and the other circumferential distanceof about 30% of the circumference, one circumferential distance of about65% of the circumference and the other circumferential distance of about35% of the circumference, one circumferential distance of about 60% ofthe circumference and the other circumferential distance of about 40% ofthe circumference, one circumferential distance of about 55% of thecircumference and the other circumferential distance of about 45% of thecircumference, or the like, depending on the specific geometry of thebicuspid aortic valve to be repaired. Thus, all asymmetric bicuspidaortic valve geometries can be repaired using the presently describedelliptical intra-annular mounting frame.

Referring now to FIG. 14, a side view of bicuspid ellipticalintra-annular mounting frame 10″ is shown. Once again bicuspidelliptical intra-annular mounting frame 10″ includes two curvatures 12″,interconnecting points 14″, and posts 16″. In the embodiment of thebicuspid elliptical intra-annular mounting frame 10″ shown in FIG. 14,the two edge portions 18″ of the bicuspid intra-annular mounting frame10″ that comprise interconnecting points 14″, posts 16″, and upperportions of the two curvatures 12″ flare outward from the vertical planeof the bicuspid elliptical intra-annular mounting frame by about10.degree. However, in other embodiments of the bicuspid ellipticalintra-annular mounting frame (not shown) the two edge portions 18″ canflare outward from the vertical plane of the intra-annular mountingframe by between about 1.degree. or so and about 30.degree. or so.Although in the embodiment of the bicuspid elliptical intra-annularmounting frame 10″ shown in FIG. 14 the two edge portions 18″ each flareoutward at equal angles from the vertical plane, in additionalembodiments (not shown) the two edge portions 18″ can flare outward fromthe vertical plane at different angles, depending on the specificgeometry of the bicuspid aortic valve to be repaired.

Most generally, the major axis of the elliptical intra-annular mountingframe is from about 10 millimeters to about 35 millimeters or so inlength, and the minor axis of the elliptical intra-annular mountingframe is from about 8 millimeters to about 25 millimeters or so inlength, with a variety of different sized frames there between, forminga gradient of possible choices to closely approximate the needs of thepatient. However, larger sizes of the elliptical intra-annular mountingframe can be produced to be utilized with patients that have aortic rootaneurysms or Marfan's syndrome. Furthermore, the ellipticalintra-annular mounting frame height as measured from the base of acurvature to the tip of a post may vary, but generally ranges from about8 millimeters to about 15 millimeters or so.

In further embodiments, the intra-annular mounting frame may be coveredwith a variety of polymers or polymer resins, including but not limitedto polyethylene terephthalate, sold under the name Dacron® cloth.Dacron® cloth is generally employed with mitral rings used in mitralvalve repair. Alternatively, the intra-annular mounting frame may becovered with gluteraldehyde-fixed bovine pericardium which is useful ashigh blood velocities in the outflow tract of the left ventricle couldpossibly predispose the patient to hemolysis with a cloth covering.

Generally, the novel intra-annular mounting frame allows repair in eventhe most dilated aortic roots, and can permanently stent and support thethree dimensional geometry of the aortic root so that further dilatationand late failure would not occur. Regarding the embodiment of theintra-annular mounting frame having posts extending from theinterconnecting points, the posts generally have a length of from about70% to about 130% of the radius of the aortic valve, and are usually ofabout a length equal to the radius of the valve. More specifically, theintra-annular mounting frame can approximate the radius of a competentaortic valve and thus increase or decrease the valve size of thediseased aortic valve to restore valve competency. In sizing theintra-annular mounting frame, the top circumference of a cusp may bemeasured and then tripled to obtain a general circumference of theaortic valve. Most preferably, 2 millimeters to about 8 millimeters willbe subtracted from this general circumference of the aortic valve todetermine the frame circumference of the intra-annular mounting frame.The subtraction of from about 2 to about 8 millimeters is preferable asthis undersizes the frame from about 0.67 millimeters to about 2.33millimeters per cusp and approximately from about 0.67 millimeters toabout 2.33 millimeters in diameter of the valve, thus allowing for thereorientation of the valve to provide greater cusp area of coaptationand valve competency. In this situation, suturing the commissuralaspects of the cusps to the embodiment of the intra-annular mountingframe with posts can eliminate much of the intercommissural dimension.Generally, the intra-annular mounting frame will reorient the nativeannulus to about a diameter of from about 16 millimeters to about 27millimeters, and preferably of from about 18 millimeters to about 25millimeters in most patients, though reorienting the aortic valve to adiameter of less than about 18 millimeters and lower generally will beavoided in order to prevent systolic gradients. Furthermore, theintra-annular mounting frame may be utilized to restore competency toprolapsed valves, wherein the diseased valve cusp is raised up andrestored to a proper orientation within the aortic wall by adjusting thespacing of the annular sutures in the frame.

One of the many advantages of the intra-annular mounting frame, is theease in which the required frame size can be determined preoperatively.Imaging techniques such as Magnetic Resonance Imaging (MRI) can be used,non-invasively, to determine the measurements of the patient's aorticvalve cusp free edge. More specifically, the measurement of an aorticvalve cusp, from one annular commissure to the other, should be equal tothe one-third of the desired valve circumference and also approximatelyequal to the annular diameter of the valve, with the height of eachcommissure roughly equivalent to the annular radius. As such, the sizeof the intra-annular mounting frame may be determined by measuring thetop circumference of a cusp of the aortic valve of a patient throughMRI, echocardiography, or other techniques, tripling the measured topcircumference of a cusp to obtain a desired annular circumference of thediseased aortic valve, and then reducing the overall circumference withthe frame to provide competency. Typically, a frame would be selectingwith a circumference from about 2 mm to about 8 mm less than thatcalculated from the cusp length. This would provide a circumferencewhich could be converted to diameter by which a variety of differentsized intra-annular mounting frame may be organized.

In further embodiments the imaging device, including an MRI machine andrelated controls, could include system parameters and mathematicaldescriptions of the model which automatically take the measurements ofthe patient's aortic valve and output the appropriately sizedintra-annular mounting frame required to restore competency of thepatient's aortic valve. Additional data output could include the displayof varying sized intra-annular mounting frames for restoring competencyand the reduction in annular diameter each different frame would createupon implantation.

Referring now to FIG. 8, there is shown intra-annular mounting frame 10opened to display a suture configuration in two dimensions with aorticvalve 18. Intra-annular mounting frame 10 may have perforations 40 oncurvatures 12 and posts 16 for the passage of sutures 42 therethrough.Sutures 42 may be horizontal mattress sutures which may then pass intothe aortic wall beneath the aortic valve annulus 20. In a preferablearrangement, sutures 42 would pass deep into the aortic wall, undercusps 22, allowing for the insertion of intra-annular mounting frame 10directly into aortic valve annulus 18 which would closely correspond tothe cusps 22 and commissures 26. Optionally, 3 horizontal mattresssutures may be utilized per cusp 22 and one per commissure 26 with atotal of 12 sutures used to implant intra-annular mounting frame 10.Obviously, lesser or more sutures as well as other attachment techniquesknown in the art may be utilized to position and attach intra-annularmounting frame 10 into aortic valve annulus 18. Above valve 18, pledgets44 may be placed onto the mattress sutures to preclude the possibletearing of aortic tissue. Pledgets 44 may be Teflon® felt pledgets or inother embodiments not illustrated; pieces or strips of fabric may beutilized with the mattress sutures rather than pledgets. Preferably,pledgets 44 may be small so they would not interfere with the mobilityof the aortic valve leaflets.

Referring now to FIG. 9, there is shown an alternative embodiment forinstalling intra-annular mounting frame 10. Support arcs 46 may beemployed above the valve annulus, into which sutures could be inserted.Support arcs 46 may comprise three curvatures with a shape that issubstantially similar to intra-annular mounting frame which correspondsto the curvature and geometry of the attachment of the cusps to theaortic wall as well as the commissures, resulting in the annulus of theaortic valve being “sandwiched” between intra-annular mounting frame 10and support arcs 46. Sutures may extend through perforations in theintra-annular mounting frame through the aortic wall to the support arcsabove the cusps, attaching also through perforations in the supportarcs. In additional embodiments, the sutures may extend around thesupport arcs or attach in other methods known in the art.

While the novel intra-annular mounting frame and related methods ofsizing and implanting the intra-annular mounting frame have beendiscussed, the present disclosure could also be applied to otherpathologies. With aortic root aneurysms, the annuloplasty frame couldallow leaflet-sparing root replacement to be performed totally frominside the aorta, without the need for extensive external dissection, aswith current procedures. A non-porous Dacron® graft may be utilized withthe intra-annular mounting frame after being scalloped and flared in thegraft's proximal aspect, to conform to the sinuses of Valsalva. The sizeof the graft may be selected to match the size of the intra-annularmounting frame, with consideration also being given for the diameter ofthe distal aorta.

The coronary arteries could then would be anastomosed to the side of thegraft, either as buttons or with the inclusion technique. Using thissimple method, the aortic valve annulus would be fixed in size andgeometry, the native aortic valve would be repaired and preserved, andthe entire root and ascending aorta could be replaced for rootaneurismal disease, with much less dissection and difficulty than withcurrent techniques.

Other pathologies also could be approached. Ultrasonic debridement couldbe used adjunctively to remove spicules of calcium, and portions ofleaflets could be resected and replaced with gluteraldehyde-fixedautologous pericardium. This concept also raises the issue of aorticvalve single cusp replacement. With a method of fixing root geometrythrough reorientation, and potentially undersizing it slightly, morecomplex repairs could be undertaken, with the frame annuloplastycompensating for slight imperfections. If one cusp were severelydiseased or prolapsing, for example, the cusp could be replaced with agluteraldehyde-fixed bovine pericardial cusp (of the appropriate sizeand geometry to match the size of the frame and native cusps). Theartificial cusp could be attached to the arc above the annuloplastyframe, with the frame acting as an attachment for the arc and artificialleaflet. Alternatively, frames could be manufactured with one bovinepericardial cusp attached to one sinus. The patient's other valve tissuecould be spared, and an entirely competent valve achieved, which thenwould be two-thirds native tissue. The pericardial leaflet tissue couldbe treated with contemporary techniques for preventing calcification,but if the artificial leaflet became immobile late postoperatively, itstill could act as a coaptation baffle for the other leaflets, andpossibly not require additional operations, as can occur with totalheterograft replacement.

The intra-annular mounting frame is unique as compared to otherapparatuses used in aortic valve repair, as the intra-annular mountingframe is designed with regard to the three-dimensional nature of theaortic valve, providing the proper anatomic geometry to the cusps andcommissures to create the necessary orientation to provide valvecompetence. The intra-annular mounting frame mounts directly to theannulus within the patient's own valve and returns the geometry of thecusps to a normal condition. Through the use of the intra-annularmounting frame's interconnecting points and preferably, the inclusion ofnarrow posts (the interconnecting points), the commissural aspect of theannulus may be raised to a proper height and orientation to producenormal cusp geometry and coaptation.

Accordingly, by the practice of the present invention, an apparatus forrestoring normal valve geometry having heretofore unrecognizedcharacteristics is disclosed. Furthermore, the present disclosureincludes the proper sizing and multiple implantation methods of theintra-annular mounting frame for the restoration of normal valvegeometry.

The disclosures of all cited patents and publications referred to inthis application are incorporated herein by reference.

The above description is intended to enable the person skilled in theart to practice the present disclosure. It is not intended to detail allof the possible variations and modifications that will become apparentto the skilled worker upon reading the description. It is intended,however, that all such modifications and variations be included withinthe scope of the present disclosure that is defined by the followingclaims. The claims are intended to cover the indicated elements andsteps in any arrangement or sequence that is effective to meet theobjectives intended for the present disclosure, unless the contextspecifically indicates the contrary.

EXAMPLES

Under regulatory supervision and informed consent, an internal geometricannuloplasty ring was implanted in 13 patients with different types ofbicuspid aortic valve disease. Two patients had Sievers Type 0 valves, 9had Sievers Type 1 valves, and 2 had Sievers Type 2. Ten patients hadleft-right cusp fusion, 1 had right-non coronary cusp fusion, and 2 hadboth. Moderate-to-severe aortic insufficiency (AI) and annulardilatation were present in 11/13 cases, and 2 patients had mild AIassociated with aortic aneurysms. The ring is constructed of one-piececomputer-machined Titanium and covered with Dacron. The device ischaracterized by circular base geometry and two subcommissural posts,positioned 180 degrees opposite on the circumference and flaring 10-15degrees outwardly from the longitudinal axis (FIG. 1A).

Required ring diameter (D) is estimated initially according tomeasurement of free-edge length (L) of the non-fused cusp using ballsizers based on the formula: Required Ring Diameter=L/2.25 (1). Thisestimate then is confirmed by placing a ring sizer within the valve, andthe diameter should almost match the inter-commissural distance (FIG.1A). Thus, the goal of the annuloplasty should not be to shorten theinter-commissural diameter, but rather to significantly reduce thesinus-to-sinus dimension. Smaller rings can be used in specificcircumstances, such as inadequate leaflet tissue, understanding thatleaflet prolapse will worsen and more leaflet plication will berequired. In the usual patient, the fused annulus usually is larger, andthe fused sinus is reduced more by the annuloplasty ring. This may haveadvantages in certain cases with less good fused leaflet mobility. Thus,geometric bicuspid ring annuloplasty produces major and reproducibleannular remodeling, while the valve is converted to a 50-50 annularconfiguration.

The chosen ring then is implanted into the aortic valve annulus beneaththe valve, with 9 trans-annular horizontal mattress sutures of 4-0polypropylene supported with fine supra-annular Dacron pledgets. Withthe ring on a holder above the valve, both ring posts are sutured to thesubcommissural regions with Cabrol-like sutures. Then, the sutures aretightened, the ring is lowered below the valve, and the holder isremoved. Seven additional “looping sutures” (3 in the non-fused annulusand 4 in the fused annulus) are placed around the ring body and passeddeeply through the aortic annulus, 2 mm beyond the leaflet-aorticjunction. This technique pulls the ring up under the annulus and avoidsany contact between ring Dacron and cusp tissue (FIG. 1B).

After tying the annular sutures with 8 knots, one needle is passed downthrough the lateral pledget and tied again, preventing subsequentleaflet injury from suture contact (2). Depending on specific anatomy,bicuspid leaflet repair then is performed (3), and ascending aorticand/or root aneurysms are replaced with remodeling techniques (5 of the13 patients in this series). The annuloplasty ring reduces annulardilatation, reshapes annular geometry, and improves leaflet coaptationby bringing both cusps symmetrically toward the midline (FIG. 2).Subsequent annular dilatation also is prevented, potentially stabilizingthe repair long-term. In the 13 patients, post-repair transesophagealechocardiograms showed Grade 0 residual AI in all, with good cuspmobility and effective height (FIG. 1B). There were no in-hospitalmortalities or major complications. During early follow-up, one patientrequired reoperation and valve replacement for a leaflet tear, and asecond patient has probable partial disruption of an autologouspericardial leaflet. A third developed endocarditis after pneumoniawhich was successfully treated medically, and he is stable withpersistent Grade 2 AI.

What is claimed is:
 1. An intra-annular mounting frame for a bicuspidaortic valve, comprising: two curvatures having ends, two pointsinterconnecting the ends of the curvatures, and two posts, such that apost extends from each point; wherein the curvatures are shaped to bereceived inside the valve below native cusps of the valve and toreorient the cusps within the valve, and wherein the posts extend fromthe points at an angle of 0 degrees to about 30 degrees when measuredfrom an internal area of a vertical plane of the frame.
 2. Theintra-annular mounting frame of claim 1, wherein the posts extend fromthe points at an angle of about 1 degree to about 30 degrees whenmeasured from an internal area of a vertical plane of the frame.
 3. Theintra-annular mounting frame of claim 1, wherein the posts extend fromthe points at an angle of about 5 degrees to about 15 degrees whenmeasured from an internal area of a latitudinal plane of the frame. 4.The intra-annular mounting frame of claim 1, wherein the length of thepost is from about 8 millimeters to about 16 millimeters.
 5. Theintra-annular mounting frame of claim 1, wherein each post has a lengthof about 70% to about 130% of the radius of the valve.
 6. Theintra-annular mounting frame of claim 1, wherein the frame has adiameter that is less than the diameter of the valve.
 7. Theintra-annular mounting frame of claim 1, wherein the frame has adiameter of about 2 millimeters to about 8 millimeters less than thediameter of the valve.
 8. The intra-annular mounting frame of claim 1,wherein the diameter of the frame ranges from about 15 millimeters toabout 30 millimeters.
 9. The intra-annular mounting frame of claim 1,wherein the length of one of the curvatures is up to about 30% largerthe other curvature.
 10. The intra-annular mounting frame of claim 1,wherein the length of one of the curvatures is up to about 20% largerthe other curvature.
 11. The intra-annular mounting frame of claim 1,wherein the length of the curvatures is substantially equal.
 12. Theintra-annular mounting frame of claim 1, wherein the posts arepositioned about 90° to about 180° apart on the circumference of theframe.
 13. The intra-annular mounting frame of claim 1, wherein theframe has an elliptical shape having a major axis and a minor axis. 14.The intra-annular mounting frame of claim 1, wherein the ratio of themajor axis to the minor axis ranges from about 1 to about 1.8.
 15. Theintra-annular mounting frame of claim 1, wherein the ratio of the majoraxis to the minor axis ranges from about 1.1 to about 1.8.
 16. Theintra-annular mounting frame of claim 1, wherein the ratio of the majoraxis to the minor axis ranges from about 1.2 to about 1.7.
 17. Theintra-annular mounting frame of claim 1, wherein the ratio of the majoraxis to the minor axis ranges is about 1.5.
 18. The intra-annularmounting frame of claim 1, wherein the frame has a non-axisymmetricshape.
 19. The intra-annular mounting frame of claim 1, wherein theframe comprises metal.
 20. The intra-annular mounting frame of claim 1,wherein the frame comprises a material selected from the groupconsisting of plastics, polymers, metal, thermoplastics, resins, andcombinations thereof.
 21. The intra-annular mounting frame of claim 1,further comprising a surface covering of a polymer fiber cloth.
 22. Theintra-annular mounting frame of claim 1, wherein the polymer fiber clothcomprises polyethylene terephthalate.